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[F. Others] F-18

Ubiquitin binding protein TRIM44 is a candidate as a novel

regulator of DNA damage response

Yonghyeon Kim¹, Jae-Hoon Ji¹, Sunwoo Min¹, Yungyeong Heo¹, Hyeseong Cho¹*

¹Department of Biochemistry, Ajou university, Suwon 16499, Korea

DNA damage response (DDR) is essential for maintaining genome stability. DDR is regulated by post-translational
modification. Ubiquitination, one of post-translation modification in DDR, was regulated by E3 ubiquitin ligase and

de-ubiquitin enzyme(DUB). Protein ubiquitylation at DNA double-strand break (DSBs) sites is critical for mobilizing
chromatin dynamics, appropriate recruitment of DDR factors, and DSB repair. Recent studies revealed that some

tripartite motif (TRIM) proteins function as E3 ubiquitin ligase and DUB, and these proteins function in autophagy,
immunity, and carcinogenesis. However, the function of TRIM proteins in DDR is not fully understood yet. To find

out novel function of TRIM proteins in DDR, we screened TRIM proteins using micro-irradiation and found that
TRIM44 were recruited at the DNA damage sites in PARP-dependent manner. We showed that depletion of TRIM44

reduced the propagation of gamma H2AX and ATM activation. We demonstrated that TRIM44 interacts with DNA
damage repair proteins via in vitro pull-down assay. Furthermore, TRIM44 depletion caused the defects in

homologous recombination repair. Taken together, our data indicate that TRIM44 is a candidate as a novel regulator
in DDR.